package main

import (
	"fmt"
	"os"
	"syscall"

	//	"strings"
	gofstab "github.com/deniswernert/go-fstab"
)

type DiskStatus struct {
	All  uint64 `json:"all"`
	Used uint64 `json:"used"`
	Free uint64 `json:"free"`
}

const (
	B  = 1
	KB = 1024 * B
	MB = 1024 * KB
	GB = 1024 * MB
)

// disk usage of path/disk
func DiskUsage(path string) (disk DiskStatus) {
	fs := syscall.Statfs_t{}
	err := syscall.Statfs(path, &fs)
	if err != nil {
		return
	}
	disk.All = fs.Blocks * uint64(fs.Bsize)
	disk.Free = fs.Bfree * uint64(fs.Bsize)
	disk.Used = disk.All - disk.Free
	return
}

func main() {
	fmt.Println("hello world !")

	var stat syscall.Statfs_t

	wd, _ := os.Getwd()

	fmt.Println("wd ==== ", wd)

	syscall.Statfs(wd, &stat)

	// Available blocks * size per block = available space in bytes
	fmt.Println(stat.Bavail * uint64(stat.Bsize))

	mounts, _ := gofstab.ParseSystem()
	fmt.Printf("%v\n", mounts)
	for _, val := range mounts {
		// fmt.Printf("%v\n",val.File)
		if val.File == "swap" || val.File == "/dev/shm" || val.File == "/dev/pts" || val.File == "/proc" || val.File == "/sys" {
			continue
		}
		disk := DiskUsage(val.File)
		// fmt.Printf("All: %.2f GB\n", float64(disk.All)/float64(GB))
		// fmt.Printf("Used: %.2f GB\n", float64(disk.Used)/float64(GB))
		// fmt.Printf("Free: %.2f GB\n", float64(disk.Free)/float64(GB))
		diskall := float64(disk.All) / float64(GB)
		diskfree := float64(disk.Free) / float64(GB)

		dfpercent := float64(diskfree / diskall)
		fmt.Printf("%s %.2f%%\n", val.File, dfpercent*100)
	}
}
